Moses g



(No Model.)

M. G. PARMER.

REGULATOR FOR ELECTRIC MOTORS.

No. 323,650. Patented Aug. 4, 1885.

'UNiTED STATES PATENT Orrlce.

MOSES G. FARMER, OF NEW YORK, N. Y.

Application filed November 13, 1584.

T 0 aZZ whom it may concern:

Be it known that I, MosEs G. FARMER, a citizen of the United States, residing in New York, in the county and State of New York, have invented certain new and useful Improvements in Electric Motors, of which the following is a specification.

My invention relates to the class of apparatus employed for converting electric energy into motion.

The object of the invention is to so organize an electric-motor system as to utilize the magnetism generated in the field-magnets in an economical manner, and to provide convenient means for rendering the revolution of the armature constant and even.

The invention consists in organizing the apparatus in substantially the following manner: A ring-armature of the Gramme type is formed, preferably,in a manner peculiarly adapted to expose considerable surface to the field-magnets, and these field-magnets are constructed with polar extensions nearly surrounding the ring of the armature. Like field-magnet poles are for this purpose presented to each other, and their ends are cut away, leaving an open- 111g of approximately the shape of the crosssection of the armature-ring. No claim, however, is herein made upon the form and con struction of the armature and fieldmagnets.

For the purpose of governing the movement of the motor I prefer to make use of the counter-current established by a second motor, the coils of which are included in circuit with the field-magnet coils of the principal motor. The rate of revolution of this second motor is automatically varied accordingly as it is desired that the principal 'motor shall itself revolve with less or greater force.

The variations in the value of the countercurre t generated by the second or the regulating motor are utilized for the purpose of neutralizing to a greater or less extent the current traversing the field-magnet coils of the primary motor.

For the purpose of controlling the rate of revolution of the regulating-motor I prefer to employ an automatically actuated brake, which is pressed with greater or less force against a friction-wheel, accordingly as the resistance offered by the machines driven by the motor is increased or decreased. For this ICATION forming part of Letters Patent No. 323,650, dated Augu 1835- (No model.)

purpose the belt coupling the two is pro vided with a wheel resting againstits surface, and this wheel is supported upon the lever carrying the brake. \Vhen the resistance offered is increased, then the belt becomes more taut,and the brake is applied with more force to the regulatingmotor, and in consequence the counter current generated is decreased and the motor is allowed to revolve with more force.

In constructing my motor I prefer to make the armature of very great size,say from twelve to twenty feet in diameter.

In the accompanying drawings, Figure 1 is a plan of an organization illustrating the invention, and showing the motor in horizontal section. Fig. 2 is a side elevation of the organization.

Referring to the drawings, A represents a suitable frame, upon which the various parts of the motor are supported. The armature B is preferably of the type known as the Gralnme ring, but instead of being of C11- cular cross-section itis preferably triangular or polygonal. This shape is adopted for the purpose of economically applying thereto the wire constituting the bobbin 1). The wire of the armature is wound in the usual manner adopted in constructing the Gram me ring. Owing to the difference in circumference at the outer and the inner portions of the ring, however, the wire is necessarily more compact at the inner side of the ring, near the axis, than at the outer circumference. It is necessary, therefore, in winding that there should either be open spaces at the outer portion, I), or else that the different convolutions should overlie each other along the interlor I)". By constructing the ring in the form shown in the drawings the latter plan may be very conveniently adopted, so that although the bobbins are of greater thickness at the inner portions, yet the width of the core and bobbin at this point will not be disproportionate to the width of the core and bobbin through the outer portion, 1). The field-magnet cores are made in the form of two U-shaped pieces having confronting poles, and these poles are enlarged, as shown in the drawings. The

faces of the poles are cut away in the proper form to permit them to encircle the ring of the armatures, the outer ends or edges of the poles being preferably united, as shown in the drawings, by bolts d, while the inner edges are separated only as great a distance as may be nec essary to permit the spokes of the armature to pass between them. The fieldanagnets are wound with coils 0, a c", and c", all so organized that a current from a main line, L, will traverse them in series and develop in the adjacent poles c and c magnetism of, say, north polarity, and in the poles c and c magnetism of south polarity. The field-magnets are vitalized by currents derived from the main line L through a branch circuit, 1 2, while coils of the armature are supplied from the main line by currents passing through a suitable commutator, F, and its brushcsf and f The operation of the motor thus constructed is well understood and does not require further description. A suitable belt-wheel, G, is applied to the axis of the motor, and from this belt-wheel power is communicated to any desired machine through a belt, h, and wheel h.

For the purpose of regulating the speed of the motor and the force with which its armature is impelled I employ an auxiliary or regulating motor,I. This motor is constructed with a field-magnet, N S, consisting, preferably, of a permanent magnet or an electromagnet vitalized by currents from an independent source and an armature, 1-, of any well-known construction. This motor is driven by the currents which traverse the coils of the fieldanagncts of the primary motor. The coils of the armaturerare for this purpose included in series with the field-magnet coils c by means of conductors 6 and 7. The currents there fore which supply the field-magnets of the principal motor are thus caused to traverse the coils of the armature of the subsidiary or regulating motor, a suitable commutator, a, being applied to the armature 1'.

It is well known that an electric motor when driven by an electric current tends to establish what is termed a counter current-that is to say, a current of the same character but in the direction opposite to that by means of which the motoris actuated. If, therefore, the field of the principal motor is established by a given current, and this current is employed for driving the regulatingmotor, a eounter-current will be established, which will depend for its strength or value upon the rapidity with which the regulatingmotor is actuated. \Vhen, for any reason, it is desired to increase the force ofthe primary motor or its rate of revolution, it will be nec essary only to decrease the rate of revolution of the regulatingmotor, and vice versa. This may be accomplished in various ways; but in this instance I have shown a brake, i, applied to a friction-wheel, it, carried upon the shaft of the regulating-motor. The brake t is carried upon a pivoted lever, 1 and this lever ismoved in one direction or the other, sous to exert a greater or less pressure upon the friction-wheel, accordingly as the force to be overcome by the motor is increased or diminished. To this end a frictional wheel, 1", is carried upon the lever 25", and this wheel rests upon the belt h. When the force to be overcome by the motor is increased-that is to say, the resistance offered by the small belt-wheel h is increased-then the tension of the side of the belt approaching the wheel G is increased also-that is to say, it is drawn into more nearly a direct line between the peripheries of the two belt-wheels, and this change in position of the belt causes the friction-wheel 6' to be moved upward, thereby increasing the pressure upon the friction-wheel t against the brake t. The counter current is thus decreased, and the regulatingmotor revolves with less speed, and the principal motor revolves with greater force.

when the resistance to be overcome by the motor is lessened, then the pressure of the brake is correspondingly lessened and the value of the counter-current is increased, and it neutralizes to a greater extent the current by means of which the principal motor is actuated.

I claim as my invention 1. The combination, substantially as here inbefore set forth, with asource of electricity, of an electricmotor included in the circuit thereof, a second electric motor included in a circuit derived from the circuit including the first-named motor, and means, substantially such as described, for modifying the rate of revolution of the first-named motor by the action of the second motor.

2. The combination, substantially as hereinbefore set forth, with an electricmotor having its field-magnet coils and its armaturecoils included in branch circuits, of a regulating electric motor included in circuit with said field-magnet coils, a brake applied to said regulating-motor, a driving belt applied to the first-named motor, and an arm or lever for controlling said brake, which arm or lever rests upon and is operated by the variations in the tension of said belt.

3. The combination, substantially as hereinbefore set forth, of an electric motor, a second motor for controlling the firstnamed motor, a belt driven by the first-named motor, and devices, substantially such as described, for controlling the rate of revolution of the second motor by the variations in the resistance offered to the first-named motor through said belt.

In testimony whereof I have hereunto subscribed my name this SOth day of October, A. D. 1884.

MOSES (l. PARKER.

Vitnesses:

SARAH J. FARMER, CHARLES A. TERRY. 

